The present invention relates to transition metal catalysts.
In the polymerization of alpha-olefins, it is known to use catalysts comprising a transition metal compound and an organometallic compound. The catalysts described above produce polymers of narrow molecular weight distribution and do not exhibit a multimodal or broad molecular weight distribution.
For many applications, such as extrusion and molding processes, it is highly desirable to have polymers which have a broad molecular weight distribution of the unimodal or the multimodal type. Such polymers evidence excellent processability, i.e., they can be processed at a faster throughput rate with lower energy requirements with reduced melt flow perturbations.
It is also highly desirable to produce multimodal or broad molecular weight distribution polymers directly in a single reactor, without having to blend polymers having different molecular weights in order to obtain the advantages of this invention.